Chifley Police District inspector Adam Beard said police and emergency services were called to the scene on the Mid-Western Highway at 11.35am.

He confirmed one female was deceased, while the male driver had been taken to Cowra hospital for further treatment. His condition is unknown.

MAP: Where the incident occurred, and where the diversions are ...

Police were seeking information into how the incident occurred, and emergency services hoped to speak to one vehicle seen travelling east.

"Police are seeking any information from the public in relation to a grey Hyundai sedan which was travelling east on the Mid-Western Highway, any witnesses are encouraged to contact police," inspector Beard said.

"At this stage there are no witnesses as to how that accident did occur so if anyone did see it take place please contact police.

A crash investigations unit was attending the scene from Sydney, and the was road expected to remain closed until that unit was able to assess the scene.

The Mid-Western Highway was been diverted from Lyndhurst to Canowindra via Belubula Way, and is expected to remain closed for several hours.

Inspector Beard also urged motorists to drive safely in the bad conditions which have gripped the Central West on Monday, with more rain and snow expected this week.

"There's a cold snap with cold, ice, bad weather ... please drive to the conditions and be safe," inspector Beard said.